This invention relates in general to articulated vehicles and, in particular, to improvements in a hitch construction for pivotally connecting a draft or tractor unit and a trailer unit so that there is adequate provision for angular movement of the units relative to each other about vertical and horizontal pivot axes when traveling over rough terrain, or the like.
More specifically, but without restriction to the particular use which is shown and described, the present invention relates to a hitch construction for use in connecting a two wheel draft unit and a trailer unit of the type employed in earth moving operations, such as, a rock wagon, or a scraper for handling earth materials, where it is necessary to transport such materials substantial distances over rough terrain.
Earthmoving or construction equipment of the wheeled type has distinct advantages over other types, such as crawler type tractors and the like, because of the higher speed of operation which is possible. However, the higher speed operation imposes severe stresses for protracted periods on the mechanism connecting the vehicles and suitable hitch constructions must be provided which are capable of withstanding the stresses. It is desirable, therefore, to provide a rugged hitch connection of relatively simple construction which is capable of easy assembly and continuous operation over long periods under heavy load conditions without excessive wear or breakage.
Hitch constructions heretofore provided for connecting vehicles of this type have comprised mountings on the rear of the tractor unit and the forward portion of the trailer unit. A vertical connecting or hitch pin, which will allow relative movement about a common vertical axis, has been mounted in the rearward portion of the tractor unit frame structure, enabling the connection to be made by inserting the hitch pin in a cooperating bearing assembly provided in the gooseneck or other forward portion of the trailer unit. Such hitch connection also provides for tilting movement of the hitch pin mounting about an axis extending in a generally horizontal plane and longitudinally of the tractor unit. With such an arrangement, the connection extends to a relatively high level on the rear of the tractor, and fluid conduits connecting between the trailer unit and the tractor unit to enable the operator to control the movement of the trailer unit in a safe and convenient manner, are exposed at a high level above the tractor frame which renders them especially vulnerable to accidental damage and interfere with an operator's line of vision.